With concrete construction, concrete is poured between one or more forms to define various surfaces of the structure. For example, a vertical concrete wall is formed between two spaced-apart vertically arranged forms. It is common to provide pass throughs through the concrete walls or formations in order to run wires, plumbing, gas lines and the like.
Current methods for forming pass throughs within concrete structures are not reliable and can become easily dislodged during the concrete pour. If this happens, and a pass through is required, the concrete must be core drilled. Core drilling can create liability issues if there are pretension cables installed in the concrete. If the pre-tension cables are damaged or destroyed during drilling, the structural integrity of the structure can be compromised. If the installer chooses not to drill through the concrete, labor and material costs increase because conduits must be strung around the structure, rather than through it.
Current methods also do not provide a concrete tight seal against the form. This can result in the form filling with concrete, rendering it useless. If the conduit is not filled with concrete, but is not flush against the form, after the form is removed, the conduit opening must be manually searched for, which is timely and expensive.
Link-Seal manufactures several pass through products, including the Link Seal, Century Line, and Cell Cast Disks. The Century-Line provides a standard length of 16 inches and consists of three components—two end caps and a sleeve. The end caps can be easily removed and lost after the forms are removed. The Link Seal product is a modular system intended to seal around the conduit and the sleeve it is seated in. Cell Cast Disks are intended to create an opening in the concrete. The disks are removed once the form is removed, leaving a hole.
High Industries manufactures a product called Double Tee Stem Block Outs, which are high cast block outs that are used in pre-cast structures and are not offered for on-site pours. The block outs are available only in specified lengths and are not sealed once the forms are removed. This allows birds, insects and animals to enter the pass through. The high cast block outs are press fit into place and may not be concrete tight. They have only one cross-sectional size.
Cooper B-Line manufactures a pipe sleeve fastener that does not provide a concrete tight seal around the conduit. They can become easily detached during the concrete pour with an expected failure rate of 20%. It is difficult to attach the Cooper parts if the form is not vertical. In addition, the Cooper parts require that each piece of conduit be cut to an exact length, which increases labor if there are variations in the form width.